1. Field of Invention
The disclosure relates to an organic light-emitting display device. More particularly, the disclosure relates to a pixel structure of the organic light-emitting display device.
2. Description of Related Art
Among various types of digital display devices, the active matrix organic light emitting display (AMOLED) device is highly competitive in a digital display device market, since the AMOLED device has advantages such as self-light-emitting, high luminance, high light-emitting efficiency, high contrast, rapid reaction speed, wide visual angle and large available temperature range.
A conventional AMOLED device includes a gate driving circuit (i.e., scan-line driving circuit), a data driving circuit and a plurality of pixel units. Each of the pixel units in the conventional AMOLED device includes an input transistor, a driving transistor, a storing capacitor and a light-emitting diode.
The gate driving circuit and the data driving circuit are respectively utilized for proving a scanning signal and a data signal to the input transistor in each of the pixel units. According to the scanning signal and the data signal, each of the pixel units controls a driving current generated by the driving transistor, such as to drive the light-emitting diode (LED) and generate lights.
However, while the AMOLED device is operating, the driving current over the light-emitting diode is affected by a threshold voltage of the driving transistor. In addition, there is a certain difference (or mismatch) existed between the threshold voltages on the driving transistors of different pixel units, and the difference of threshold voltages between different pixel units may lead to a luminance distortion between pixel units, and further to decrease the display quality of the AMOLED device.